androidx.leanback.widget

The core interface to the developer’s model is the
ObjectAdapter. It is similar to Adapter and the
RecyclerView Adapter, but separates iterating items from presenting them as Views.
Concrete implementations include
ArrayObjectAdapter and
CursorObjectAdapter, but a developer is free to use a
subclass of an ObjectAdapter to iterate over any existing Object hierarchy.

A Presenter creates Views and binds data from an Object
to those Views. This is the
complementary piece to ObjectAdapter that corresponds to existing Android adapter classes.
The benefit to separating out a Presenter is that we can use it to generate Views outside of the
context of an adapter. For example, a UI may represent data from a single Object in several places
at once. Each View that needs to be generated can be produced by a different Presenter, while the
Object is retrieved from the ObjectAdapter once.

A PresenterSelector determines which Presenter to use
for a given Object from an
ObjectAdapter. Two common cases are when an ObjectAdapter uses the same View type for every element
(SinglePresenterSelector), and when the Presenter is
determined by the Java class of
the element (ClassPresenterSelector). A developer is
able to implement any selection logic
as a PresenterSelector. For example, if all the elements of an ObjectAdapter have the same type,
but certain elements are to be rendered using a 'promotional content' view in the developer’s
application, the PresenterSelector may inspect the fields of each element before choosing the
appropriate Presenter.

The basic navigation model for Leanback is that of a vertical list of rows, each of which may
be a horizontal list of items. Therefore, Leanback uses ObjectAdapters both for defining the
horizontal data items as well as the list of rows themselves.

Leanback defines a few basic data model classes for rows: the
Row, which defines the
abstract concept of a row with a header; and ListRow,
a concrete Row implementation that uses an ObjectAdapter to present a horizontal list of items.
The corresponding presenter for the ListRow is the
ListRowPresenter.

Other types of Rows and corresponding RowPresenters are provided; however the application may
define a custom subclass of Row and
RowPresenter.

This interface is deprecated.
Launching voice recognition activity is no longer supported. App should declare
android.permission.RECORD_AUDIO in AndroidManifest file. See details in
SearchSupportFragment.